1. Field of the Invention
The present invention relates to an image forming system including an image forming apparatus and sheet processing apparatuses, and relates to a sheet processing apparatus.
2. Description of the Related Art
Conventionally, there has been known an image forming system having post-processing apparatuses such as a finisher which are coupled with an image forming apparatus, e.g., a copier, to achieve various post-processing desired by a user. For a business operation called POD (print-on demand) to print a desired number of sets of prints when needed, such an apparatus is desired which is suitable for fast and diversified small quantity production, i.e., which does not need to make preparation of printing-plate, adjustment or setting of bookbinder, and other preparation at change in types of prints.
By using an image forming apparatus in combination with apparatuses dedicated to post-processing, it is possible to rapidly output various products desired by a user (e.g., bookbound sheet bundles, processed sheets, etc.). As the post-processing, there may be mentioned punching, sheet bundle discharging, stitching, folding, bookbinding, gluing, lapping, sorting, inserting, etc.
There has also been proposed an image forming apparatus capable of being activated simply by initializing a basic part thereof, while deciding the configuration of an image forming system based on system information stored in a nonvolatile memory, without confirming connection states of post-processing apparatuses upon activation of the image forming apparatus (see, Japanese Laid-open Patent Publication No. 2006-23611). With this image forming apparatus, a system activation time can be shortened.
However, these conventional image forming systems entail the following problems. Specifically, the POD system for diversified small quantity production needs to frequently change its configuration to attain the optimum system arrangement that varies depending on the type of job. Therefore, it takes much time including communication time to process configuration information, resulting in increase of a user's waiting time at activation of the system.
If the configuration of an image forming system is decided based on system information stored in a nonvolatile memory, without confirming states of connection between post-processing apparatuses and the image forming apparatus at the turn-on of power supply, as disclosed in Japanese Laid-open Patent Publication No. 2006-23611, problems are caused that it becomes difficult to deal with configuration information details such as a sequence alteration between the post-processing apparatuses and the presence/absence of and/or positions of an option tray, dolly, adapter and cartridge in the post-processing apparatuses.
Japanese Laid-open Patent Publication No. 2008-090274 discloses an image forming system, in which a downstream-most option peripheral device transmits option configuration information (initial information) to an upstream option peripheral device that adds its own option configuration information to the configuration information received from the downstream-most device and transmits the resultant option configuration information to a further upstream option device or an image forming apparatus. With this system, however, if each of the option devices has its power source configured to be singly and independently turned on/off by a user, it takes much time to grasp the configuration of the image forming system unless the user turns on the power sources of the option devices in sequence from the downstream-most device to the upstream-most device.